Castell Dinerth

near Aberarth, Ceredigion, west Wales

Richard Hartnup, The University of Wales, Aberystwyth.

Dinerth, or Dineirth (possibly from Dinarth - the fort on the Arth?) castle
has also been called "Hero" castle. [Granville Thomas points out another
possible Scandinavian influence here, as "Hiro" is a word meaning the king's
carl, or vassal lord - See Lôn Lacs below]. The castle is a motte and
bailey construction, like Castell Trefilan and Castell Gwallter visited in
previous classes. Dinerth was originally built by the de Clare family
around 1110. It has had an extremely chequered history - razed by Gruffydd
ap Rees in 1116, and again by Owain of Gwynedd in 1136. It was occupied by
Hywel in 1143, and by Cadwaladr in the following year. In 1158 it became
part of the lands ceded by the Normans to Earl Roger of Hereford. It was
destroyed yet again by Lord Rhys in 1164, and came into the possession of
Maelgwyn who lost it to his brother, but recovered it in 1199. It is
thought to have been completely destroyed by Maelgwyn in 1202 - to prevent
it falling into the hands of Llewelyn. Considering its history, it might
have been worth letting Llewelyn have it! It had been razed three times,
and changed hands at least six times in a period of about 90 years.

The castle is on a promontory, or spur of land between the Arth and its
tributary, the Nant Erthig. There could well have been a prehistoric
defence structure here that was adapted in mediaeval times. There is a
strong ditch and linear ridge defence on the eastern side, whilst all other
sides fall into steep ravines. There seem to be three separate mounds
within the site which covers about 3 ha. The entire area is covered with
ancient oak and beech woodland with a very diverse ground flora.